为解决高功率固体激光系统空间滤波小孔堵孔问题, 针对空间滤波小孔中的等离子体溅射现象, 对等离子体扩散１维分布模型进行了分析。分别对铝、金和碳等３种典型材料１维分布情况及扩散速度进行了数值模拟, 得到等离子体扩散速度大约为107 cm/s。根据模拟计算结果, 分析了神光Ⅲ原型装置助推放大级的堵孔风险, 结果表明, 在长脉冲情况下等离子体溅射造成的影响不可忽略。

The pinhole closure phenomena in spatial filter of high power solid-state laser system might limit the output energy and affect the safe operation of the laser system. The distribution of plasma created by intense laser radiation is studied. The numerical simulation of one dimensional plasma distribution of three typical materials (Al, Au, C) is illustrated. The simulation demonstrates that the diffusion velocity of plasma is about 107 cm/s. The possibility of pinhole closure in the boost amplifier of SG Ⅲ plototype is analyzed, which indicates that the pinhole closure under long pulse laser irradiation is not negligible．